/*! Backstretch - v2.0.3 - 2012-11-30
 * http://srobbin.com/jquery-plugins/backstretch/
 * Copyright (c) 2012 Scott Robbin; Licensed MIT */
define("plugins/backstretch/jquery.backstretch",[],function(require, exports, module) {

  (function($, window, undefined) {
    'use strict';

    /* PLUGIN DEFINITION
     * ========================= */

    $.fn.backstretch = function(images, options) {
      // We need at least one image
      if (images === undefined || images.length === 0) {
        $.error("No images were supplied for Backstretch");
      }

      /*
       * Scroll the page one pixel to get the right window height on iOS
       * Pretty harmless for everyone else
       */
      if ($(window).scrollTop() === 0) {
        window.scrollTo(0, 0);
      }

      return this.each(function() {
        var $this = $(this),
          obj = $this.data('backstretch');

        // If we've already attached Backstretch to this element, remove the old instance.
        if (obj) {
          // Merge the old options with the new
          options = $.extend(obj.options, options);

          // Remove the old instance
          obj.destroy(true);
        }

        obj = new Backstretch(this, images, options);
        $this.data('backstretch', obj);
      });
    };

    // If no element is supplied, we'll attach to body
    $.backstretch = function(images, options) {
      // Return the instance
      return $('body')
        .backstretch(images, options)
        .data('backstretch');
    };

    // Custom selector
    $.expr[':'].backstretch = function(elem) {
      return $(elem).data('backstretch') !== undefined;
    };

    /* DEFAULTS
     * ========================= */

    $.fn.backstretch.defaults = {
      centeredX: true // Should we center the image on the X axis?
        ,
      centeredY: true // Should we center the image on the Y axis?
        ,
      duration: 5000 // Amount of time in between slides (if slideshow)
        ,
      fade: 0 // Speed of fade transition between slides
    };

    /* STYLES
     *
     * Baked-in styles that we'll apply to our elements.
     * In an effort to keep the plugin simple, these are not exposed as options.
     * That said, anyone can override these in their own stylesheet.
     * ========================= */
    var styles = {
      wrap: {
        left: 0,
        top: 0,
        overflow: 'hidden',
        margin: 0,
        padding: 0,
        height: '100%',
        width: '100%',
        zIndex: -999999
      },
      img: {
        position: 'absolute',
        display: 'none',
        margin: 0,
        padding: 0,
        border: 'none',
        width: 'auto',
        height: 'auto',
        maxWidth: 'none',
        zIndex: -999999
      }
    };

    /* CLASS DEFINITION
     * ========================= */
    var Backstretch = function(container, images, options) {
      this.options = $.extend({}, $.fn.backstretch.defaults, options || {});

      /* In its simplest form, we allow Backstretch to be called on an image path.
       * e.g. $.backstretch('/path/to/image.jpg')
       * So, we need to turn this back into an array.
       */
      this.images = $.isArray(images) ? images : [images];

      // Preload images
      $.each(this.images, function() {
        $('<img />')[0].src = this;
      });

      // Convenience reference to know if the container is body.
      this.isBody = container === document.body;

      /* We're keeping track of a few different elements
       *
       * Container: the element that Backstretch was called on.
       * Wrap: a DIV that we place the image into, so we can hide the overflow.
       * Root: Convenience reference to help calculate the correct height.
       */
      this.$container = $(container);
      this.$wrap = $('<div class="backstretch"></div>').css(styles.wrap).appendTo(this.$container);
      this.$root = this.isBody ? supportsFixedPosition ? $(window) : $(document) : this.$container;

      // Non-body elements need some style adjustments
      if (!this.isBody) {
        // If the container is statically positioned, we need to make it relative,
        // and if no zIndex is defined, we should set it to zero.
        var position = this.$container.css('position'),
          zIndex = this.$container.css('zIndex');

        this.$container.css({
          position: position === 'static' ? 'relative' : position,
          zIndex: zIndex === 'auto' ? 0 : zIndex,
          background: 'none'
        });

        // Needs a higher z-index
        this.$wrap.css({
          zIndex: -999998
        });
      }

      // Fixed or absolute positioning?
      this.$wrap.css({
        position: this.isBody && supportsFixedPosition ? 'fixed' : 'absolute'
      });

      // Set the first image
      this.index = 0;
      this.show(this.index);

      // Listen for resize
      $(window).on('resize.backstretch', $.proxy(this.resize, this))
        .on('orientationchange.backstretch', $.proxy(function() {
          // Need to do this in order to get the right window height
          if (this.isBody && window.pageYOffset === 0) {
            window.scrollTo(0, 1);
            this.resize();
          }
        }, this));
    };

    /* PUBLIC METHODS
     * ========================= */
    Backstretch.prototype = {
      resize: function() {
        try {
          var bgCSS = {
              left: 0,
              top: 0
            },
            rootWidth = this.isBody ? this.$root.width() : this.$root.innerWidth(),
            bgWidth = rootWidth,
            rootHeight = this.isBody ? (window.innerHeight ? window.innerHeight : this.$root.height()) : this.$root.innerHeight(),
            bgHeight = bgWidth / this.$img.data('ratio'),
            bgOffset;

          // Make adjustments based on image ratio
          if (bgHeight >= rootHeight) {
            bgOffset = (bgHeight - rootHeight) / 2;
            if (this.options.centeredY) {
              bgCSS.top = '-' + bgOffset + 'px';
            }
          } else {
            bgHeight = rootHeight;
            bgWidth = bgHeight * this.$img.data('ratio');
            bgOffset = (bgWidth - rootWidth) / 2;
            if (this.options.centeredX) {
              bgCSS.left = '-' + bgOffset + 'px';
            }
          }

          this.$wrap.css({
              width: rootWidth,
              height: rootHeight
            })
            .find('img:not(.deleteable)').css({
              width: bgWidth,
              height: bgHeight
            }).css(bgCSS);
        } catch (err) {
          // IE7 seems to trigger resize before the image is loaded.
          // This try/catch block is a hack to let it fail gracefully.
        }

        return this;
      }

      // Show the slide at a certain position
      ,
      show: function(index) {
        // Validate index
        if (Math.abs(index) > this.images.length - 1) {
          return;
        } else {
          this.index = index;
        }

        // Vars
        var self = this,
          oldImage = self.$wrap.find('img').addClass('deleteable'),
          evt = $.Event('backstretch.show', {
            relatedTarget: self.$container[0]
          });

        // Pause the slideshow
        clearInterval(self.interval);

        // New image
        self.$img = $('<img />')
          .css(styles.img)
          .bind('load', function(e) {
            var imgWidth = this.width || $(e.target).width(),
              imgHeight = this.height || $(e.target).height();

            // Save the ratio
            $(this).data('ratio', imgWidth / imgHeight);

            // Show the image, then delete the old one
            // "speed" option has been deprecated, but we want backwards compatibilty
            $(this).fadeIn(self.options.speed || self.options.fade, function() {
              oldImage.remove();

              // Resume the slideshow
              if (!self.paused) {
                self.cycle();
              }

              // Trigger the event
              self.$container.trigger(evt, self);
            });

            // Resize
            self.resize();
          })
          .appendTo(self.$wrap);

        // Hack for IE img onload event
        self.$img.attr('src', self.images[index]);
        return self;
      }

      ,
      next: function() {
        // Next slide
        return this.show(this.index < this.images.length - 1 ? this.index + 1 : 0);
      }

      ,
      prev: function() {
        // Previous slide
        return this.show(this.index === 0 ? this.images.length - 1 : this.index - 1);
      }

      ,
      pause: function() {
        // Pause the slideshow
        this.paused = true;
        return this;
      }

      ,
      resume: function() {
        // Resume the slideshow
        this.paused = false;
        this.next();
        return this;
      }

      ,
      cycle: function() {
        // Start/resume the slideshow
        if (this.images.length > 1) {
          // Clear the interval, just in case
          clearInterval(this.interval);

          this.interval = setInterval($.proxy(function() {
            // Check for paused slideshow
            if (!this.paused) {
              this.next();
            }
          }, this), this.options.duration);
        }
        return this;
      }

      ,
      destroy: function(preserveBackground) {
        // Stop the resize events
        $(window).off('resize.backstretch orientationchange.backstretch');

        // Clear the interval
        clearInterval(this.interval);

        // Remove Backstretch
        if (!preserveBackground) {
          this.$wrap.remove();
        }
        this.$container.removeData('backstretch');
      }
    };

    /* SUPPORTS FIXED POSITION?
     *
     * Based on code from jQuery Mobile 1.1.0
     * http://jquerymobile.com/
     *
     * In a nutshell, we need to figure out if fixed positioning is supported.
     * Unfortunately, this is very difficult to do on iOS, and usually involves
     * injecting content, scrolling the page, etc.. It's ugly.
     * jQuery Mobile uses this workaround. It's not ideal, but works.
     *
     * Modified to detect IE6
     * ========================= */

    var supportsFixedPosition = (function() {
      var ua = navigator.userAgent,
        platform = navigator.platform
        // Rendering engine is Webkit, and capture major version
        ,
        wkmatch = ua.match(/AppleWebKit\/([0-9]+)/),
        wkversion = !!wkmatch && wkmatch[1],
        ffmatch = ua.match(/Fennec\/([0-9]+)/),
        ffversion = !!ffmatch && ffmatch[1],
        operammobilematch = ua.match(/Opera Mobi\/([0-9]+)/),
        omversion = !!operammobilematch && operammobilematch[1],
        iematch = ua.match(/MSIE ([0-9]+)/),
        ieversion = !!iematch && iematch[1];

      return !(
        // iOS 4.3 and older : Platform is iPhone/Pad/Touch and Webkit version is less than 534 (ios5)
        ((platform.indexOf("iPhone") > -1 || platform.indexOf("iPad") > -1 || platform.indexOf("iPod") > -1) && wkversion && wkversion < 534) ||

        // Opera Mini
        (window.operamini && ({}).toString.call(window.operamini) === "[object OperaMini]") ||
        (operammobilematch && omversion < 7458) ||

        //Android lte 2.1: Platform is Android and Webkit version is less than 533 (Android 2.2)
        (ua.indexOf("Android") > -1 && wkversion && wkversion < 533) ||

        // Firefox Mobile before 6.0 -
        (ffversion && ffversion < 6) ||

        // WebOS less than 3
        ("palmGetResource" in window && wkversion && wkversion < 534) ||

        // MeeGo
        (ua.indexOf("MeeGo") > -1 && ua.indexOf("NokiaBrowser/8.5.0") > -1) ||

        // IE6
        (ieversion && ieversion <= 6)
      );
    }());

  }(jQuery, window));

});